Red Wrigglers work OK for aquatic frogs; but most terrestrial ones are put off by the foul tasting slime they make to the point of some frogs rejecting any earthworms later. Canadian or European Night Crawlers are a much better choice as feeders Brian .
If swallowed whole they don't get a chance to secrete their defense. As long as the frog is large enough to swallow Red Wigglers whole they will not rejects them.